Front-page polish: hero lead card + title-cased labels

Render the #1 Top Story as an Apple-News-style hero card (flat surface, 4pt
stripe, 24pt headline, summary, sources, prominent score). Prettify category
labels (slug -> Title Case, with AI/US/Formula 1 special-cases) across rows,
hero, and detail. Per Emil's framework, no row entrance/press motion on a
constantly-scrolled surface — invest in hierarchy and defaults instead.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Jarvis/Views/Shared/Theme.swift

@@ -106,11 +106,15 @@ enum Signal {
 enum Topic {
     static func label(_ slug: String) -> String {
         switch slug.lowercased() {
-        case "finance":  return "Finance"
-        case "tech":     return "Tech"
-        case "politics": return "Politics"
-        case "africa":   return "Africa"
-        default:         return slug.prefix(1).uppercased() + slug.dropFirst()
+        case "ai", "artificial-intelligence": return "AI"
+        case "us", "united-states":           return "US"
+        case "formula-1":                     return "Formula 1"
+        case "ui-ux", "web-design-and-ui-ux": return "Web Design"
+        default:
+            // Slug → Title Case, e.g. "cloud-computing" → "Cloud Computing".
+            return slug.split(separator: "-")
+                .map { $0.prefix(1).uppercased() + $0.dropFirst() }
+                .joined(separator: " ")
         }
     }